Although groups such as the Cahaba River Society and The Nature Conservancy argued that the expansion was necessary to protect the Cahaba's water quality, other commentators questioned the proposed price tag of the expansion -- estimated by USFWS at $290 million.

The U.S. Fish and Wildlife Service announced Monday that it "will take six months to review its options about how to proceed with a proposed expansion of the Cahaba [River] National Wildlife Refuge's acquisition boundary."

In Georgia and Tennessee, most of the sandstone ridges are relatively narrow, but in Alabama, the region also includes the Coosa and Cahaba ridges that are broader and of younger Pennsylvanian-age sandstone and shale.